Banks are worse than casinos, claims Greg Smith, the former Goldman Sachs executive who hit the headlines last year when he said the investment bank treated its clients like Muppets.

In his first interview to coincide with the publication of his book Why I Left Goldman Sachs yesterday, Mr Smith, pictured, told Associated Press: "Right now the system is stacked against everyone else in favour of the banks.

"It's a little like a casino. A real casino is regulated and there are cameras everywhere and the casino cannot see your cards.

"With Wall Street today, the bank can see what every government, every pension fund, every hedge fund in the world is doing. They can effectively see everyone's cards.

"Then, instead of facilitating the client's will, they're trying to get the client to facilitate their will."

Mr Smith claimed when his warts-and-all piece appeared in the New York Times last year he received many supportive emails from Goldman clients and even from some of the bank's managing directors.